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        1 2     

  Subjects -> VETERINARY SCIENCE (Total: 170 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access  
Acta Veterinaria Brno     Open Access   (1 follower)
Acta Veterinaria Hungarica     Full-text available via subscription   (1 follower)
Acta Veterinaria Scandinavica     Open Access   (1 follower)
Advances in Animal Biosciences     Full-text available via subscription   (5 followers)
Advances in Veterinary Medicine     Full-text available via subscription   (5 followers)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (8 followers)
American Journal of Animal and Veterinary Sciences     Open Access   (7 followers)
American Journal of Primatology     Hybrid Journal   (5 followers)
American Journal of Veterinary Research     Full-text available via subscription   (15 followers)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (2 followers)
Animal Behaviour     Hybrid Journal   (129 followers)
Animal Feed Science and Technology     Hybrid Journal   (4 followers)
Animal Health Research Reviews     Hybrid Journal   (4 followers)
Animal Reproduction Science     Hybrid Journal   (4 followers)
Animals     Open Access   (5 followers)
Annales UMCS, Medicina Veterinaria     Open Access  
Annals of Agricultural and Environmental Medicine     Open Access   (1 follower)
Annual Review of Animal Biosciences     Full-text available via subscription   (4 followers)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (3 followers)
Archives of Animal Nutrition     Hybrid Journal   (3 followers)
Archivos de Medicina Veterinaria     Open Access   (1 follower)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (1 follower)
Asian Journal of Poultry Science     Open Access   (1 follower)
Australian Equine Veterinarian     Full-text available via subscription   (1 follower)
Australian Veterinary Journal     Hybrid Journal   (10 followers)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (3 followers)
Avian Diseases Digest     Full-text available via subscription   (2 followers)
Avian Pathology     Hybrid Journal   (1 follower)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access  
BMC Veterinary Research     Open Access   (5 followers)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (5 followers)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (4 followers)
Case Reports in Veterinary Medicine     Open Access   (3 followers)
Ciência Rural     Open Access   (2 followers)
Companion Animal     Hybrid Journal   (4 followers)
Continental Journal of Animal and Veterinary Research     Open Access   (3 followers)
Continental Journal of Veterinary Sciences     Open Access   (3 followers)
Domestic Animal Endocrinology     Hybrid Journal   (3 followers)
Equine Veterinary Education     Hybrid Journal   (7 followers)
Equine Veterinary Journal     Hybrid Journal   (9 followers)
Ethiopian Veterinary Journal     Open Access  
Eurasian Journal of Veterinary Sciences     Open Access   (1 follower)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (5 followers)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (3 followers)
Indian Journal of Animal Sciences     Open Access   (4 followers)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (3 followers)
International Journal for Agro Veterinary and Medical Sciences     Open Access   (3 followers)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (1 follower)
InVet     Open Access  
Irish Veterinary Journal     Open Access   (2 followers)
ISRN Veterinary Science     Open Access   (5 followers)
Journal of Veterinary Science & Technology     Open Access   (3 followers)
Journal of Animal Behaviour and Biometeorology     Open Access   (1 follower)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (3 followers)
Journal of Applied Animal Nutrition     Hybrid Journal   (1 follower)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (4 followers)
Journal of Equine Veterinary Science     Hybrid Journal   (8 followers)
Journal of Exotic Pet Medicine     Full-text available via subscription   (2 followers)
Journal of Experimental and Applied Animal Sciences     Open Access   (1 follower)
Journal of Feline Medicine & Surgery     Hybrid Journal   (3 followers)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (8 followers)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (19 followers)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (1 follower)
Journal of the South African Veterinary Association     Open Access   (1 follower)
Journal of Venomous Animals and Toxins     Open Access   (3 followers)
Journal of Veterinary Advances     Open Access   (4 followers)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (3 followers)
Journal of Veterinary Cardiology     Full-text available via subscription   (4 followers)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (4 followers)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (9 followers)
Journal of Veterinary Internal Medicine     Hybrid Journal   (11 followers)
Journal of Veterinary Medical Education     Partially Free   (8 followers)
Journal of Veterinary Medicine     Open Access   (2 followers)
Journal of Veterinary Medicine and Animal Health     Open Access  
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (4 followers)
Journal of Veterinary Science & Medical Diagnosis     Full-text available via subscription  
Journal of Zoo and Aquarium Research     Open Access  
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (2 followers)
Kenya Veterinarian     Full-text available via subscription  
kleintier konkret     Hybrid Journal  
Livestock     Hybrid Journal  
Macedonian Veterinary Review     Open Access   (3 followers)
MEDIA PETERNAKAN - Journal of Animal Science and Technology     Open Access   (1 follower)
Medical Mycology     Open Access   (2 followers)
Medical Mycology Case Reports     Open Access  
Microbes and Health     Open Access   (2 followers)
New Zealand Veterinary Journal     Full-text available via subscription   (7 followers)
New Zealand Veterinary Nurse     Full-text available via subscription   (2 followers)
Nigerian Veterinary Journal     Open Access  
Onderstepoort Journal of Veterinary Research     Open Access   (2 followers)
Open Access Animal Physiology     Open Access   (2 followers)

        1 2     

Veterinary Microbiology    [10 followers]  Follow    
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
     Published by Elsevier Homepage  [2556 journals]   [SJR: 1.221]   [H-I: 75]
  • Cytokine and chemokine mRNA expression profiles in BALF cells isolated
           from pigs single infected or co-infected with swine influenza virus and
           Bordetella bronchiseptica
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Andrzej Kowalczyk , Małgorzata Pomorska-Mól , Krzysztof Kwit , Zygmunt Pejsak , Jarosław Rachubik , Iwona Markowska-Daniel
      Pigs serve as a valuable animal experimental model for several respiratory pathogens, including Swine Influenza Virus (SIV) and Bordetella bronchiseptica (Bbr). To investigate the effect of SIV and Bbr coinfection on cytokine and viral RNA expression, we performed a study in which pigs were inoculated with SIV, Bbr or both pathogens (SIV/Bbr). Our results indicate that Bbr infection alters SIV clearance. Pulmonary lesions in the SIV/Bbr group were more severe when compared to SIV or Bbr groups and Bbr did not cause significant lesions. Broncho-alveolar lavage fluid (BALF) was examined for inflammatory mediators by qPCR. Interferon (IFN)-α, interleukin IL-8, IL-1 peaked in BALF at 2 DPI, while the virus titres and severity of clinical signs were maximal at the same time. Despite its increased expression in co-infected pigs, interferon-α did not enhance SIV clearance, since the viral replication was detected at the same day as the highest IFN levels. The mRNA levels for IFN-α, IL-1β and IL-8 were significantly higher in BALF of co-infected pigs and correlated with enhanced viral RNA titers in lungs, trachea and nasal swabs. Transcription of mRNA for IL-1β was stable in SIV and SIV/Bbr groups throughout all the study. In Bbr group, the levels of mRNAs for IL-1β were significantly higher at 2, 4 and 9 DPI. The mean levels of mRNAs for TNF-α were lower than the levels of other chemokines and cytokines in all infected groups. Transcript levels of IL-10 and IL-4 did not increase at each time points. Overall, SIV replication was increased by Bbr presence and the enhanced production of pro-inflammatory mediators could contribute to the exacerbated pulmonary lesions.


      PubDate: 2014-04-12T15:27:23Z
       
  • IFC - Aims & Scope, EDB, Publication Information
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4




      PubDate: 2014-04-12T15:27:23Z
       
  • Diagnostic utility of CD4%:CD8low% T-lymphocyte ratio to differentiate
           feline immunodeficiency virus (FIV)-infected from FIV-vaccinated cats
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Annette Litster , Jui-Ming Lin , Jamieson Nichols , Hsin-Yi Weng
      Antibody testing based on individual risk assessments is recommended to determine feline immunodeficiency virus (FIV) status, but ELISA and Western blot tests cannot distinguish between anti-FIV antibodies produced in response to natural infection and those produced in response to FIV vaccination. The aim of this cross-sectional study was to test the hypothesis that FIV-infected cats could be differentiated from FIV-vaccinated uninfected cats using lymphocyte subset results, specifically the CD4%:CD8low% T-lymphocyte ratio. Comparisons of the CD4%:CD8low% T-lymphocyte ratio were made among the following four groups: Group 1 – FIV-infected cats (n =61; FIV-antibody positive by ELISA and FIV PCR positive); Group 2 – FIV-uninfected cats (n =96; FIV-antibody negative by ELISA); Group 3 – FIV-vaccinated uninfected cats (n =31; FIV-antibody negative by ELISA before being vaccinated against FIV, after which they tested FIV ELISA positive); and Group 4 – FIV-uninfected but under chronic/active antigenic stimulation (n =16; FIV-antibody negative by ELISA; all had active clinical signs of either upper respiratory tract disease or gingival disease for ≥ 21 days). The median CD4%:CD8low% T-lymphocyte ratio was lower in Group 1 (1.39) than in each of the other three groups (Group 2 – 9.77, Group 3 – 9.72, Group 4 – 5.64; P <0.05). The CD4%:CD8low% T-lymphocyte ratio was also the most effective discriminator between FIV-infected cats and the other three groups, and areas under ROC curves ranged from 0.91 (compared with Group 4) to 0.96 (compared with Group 3). CD4%:CD8low% shows promise as an effective test to differentiate between FIV-infected cats and FIV-vaccinated uninfected cats.


      PubDate: 2014-04-12T15:27:23Z
       
  • A current review of avian influenza in pigeons and doves (Columbidae)
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Celia Abolnik
      Recent reports of the detection of the zoonotic low pathogenic avian influenza (LPAI) H7N9 viruses in healthy pigeons have again put the spotlight on the potential role of pigeons and doves in the transmission of avian influenza between infected poultry and humans. A surge in studies followed the highly pathogenic avian influenza (HPAI) H5N1 epidemic, and this review collates the new data on AIV in pigeons and doves, both from a surveillance perspective, as well as the results of numerous clinical studies. Collectively, results of 32 field studies representing 24 countries across four continents indicate an antibody prevalence of 8.01% in pigeons and doves but only 0.37% of the total was associated with exposure to the same serotype as a highly pathogenic avian influenza (HPAI) outbreak occurring in poultry at the time. Only 1.1% of 6155 columbids sampled tested positive for the virus, and only 9/6155 (0.15%) viruses were detected in regions that were experiencing outbreaks of a notifiable serotype at the time. In 22 experimental infection studies with HPAI and LPAI viruses since 1944, only 26/715 (3.64%) mortalities were reported, and these could usually be associated with excessive doses of inoculum, which would induce fatal inflammatory responses. Since seroconversion and virus detection was demonstrated in many of these studies, albeit without clinical signs in most cases, it is clear that columbids are susceptible to infection, but ineffective propagators and disseminators of the virus, i.e. “dead end” hosts for AIVs, even HPAI. Viruses are shed in minute quantities from both the choana and in the feces for a short duration but titers are below the minimum threshold require to infect other species.


      PubDate: 2014-04-12T15:27:23Z
       
  • Equus asinus Papillomavirus (EaPV1) provides new insights into equine
           papillomavirus diversity
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): R. Lecis , G. Tore , A. Scagliarini , E. Antuofermo , C. Dedola , C. Cacciotto , G.M. Dore , E. Coradduzza , L. Gallina , M. Battilani , A.G. Anfossi , M. Muzzeddu , B. Chessa , M. Pittau , A. Alberti
      We detected a novel papillomavirus (EaPV1) from healthy skin and from sun associated cutaneous lesions of an Asinara (Sardinia, Italy) white donkey reared in captivity in a wildlife recovery centre. The entire genome of EaPV1 was cloned, sequenced, and characterised. Genome is 7467bp long, and shows some characteristic elements of horse papillomaviruses, including a small untranslated region between the early and late regions and the lack of the retinoblastoma tumour suppressor binding domain LXCXE in E7. Additionally, a typical E6 ORF is missing. EaPV1 DNA was detected in low copies in normal skin of white and grey donkeys of the Asinara Island, and does not transform rodent fibroblasts in standard transformation assays. Pairwise nucleotide alignments and phylogenetic analyses based on concatenated E1-E2-L1 amino acid sequences revealed the highest similarity with the Equine papillomavirus type 1. The discovery of EaPV1, the prototype of a novel genus and the first papillomavirus isolated in donkeys, confirms a broad diversity in Equidae papillomaviruses. Taken together, data suggest that EaPV1 is a non-malignant papillomavirus adapted to healthy skin of donkeys.


      PubDate: 2014-04-12T15:27:23Z
       
  • DIVA vaccine properties of the live chimeric pestivirus strain CP7_E2gif
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Tanya von Rosen , Desislava Rangelova , Jens Nielsen , Thomas Bruun Rasmussen , Åse Uttenthal
      Live modified vaccines to protect against classical swine fever virus (CSFV), based on chimeric pestiviruses, have been developed to enable serological Differentiation of Infected from Vaccinated Animals (DIVA). In this context, the chimeric virus CP7_E2gif vaccine candidate is unique as it does not include any CSFV components. In the present study, the DIVA vaccine properties of CP7_E2gif were evaluated in comparison to the conventional live attenuated Riemser C-strain vaccine. Sera and tonsil samples obtained from pigs immunised with these two vaccines were analysed. No viral RNA was found in serum after vaccination with CP7_E2gif, whereas some serum samples from C-strain vaccinated animals were positive. In both vaccinated groups, individual viral RNA-positive tonsil samples were detected in animals euthanised between 7 and 21 days post vaccination. Furthermore, serum samples from these animals, together with archival samples from pigs vaccinated with CP7_E2gif and subsequently CSFV challenged, were analysed for specific antibodies using ELISAs and for homologous neutralising antibodies. In animals vaccinated with CP7_E2gif, neutralising antibodies were detected from day 10. However, the sera remained negative for anti-CSFV E2-specific antibodies whereas pigs vaccinated with C-strain seroconverted against CSFV by 14 days after vaccination, as determined by a CSFV-E2 specific blocking ELISA. One week after subsequent CSFV challenge, a strong anti-CSFV E2 reaction was detected in CP7_E2gif vaccinated pigs and anti-Erns antibodies were detected from 10 days after infection. In conclusion, CP7_E2gif has the potential to be used as a DIVA vaccine in combination with detection of anti-CSFV E2-specific antibodies.


      PubDate: 2014-04-12T15:27:23Z
       
  • Genomic analysis and pathogenic characteristics of Type 2 porcine
           reproductive and respiratory syndrome virus nsp2 deletion strains isolated
           in Korea
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Hwan-Won Choi , Eeuri Nam , Yoo Jin Lee , Yun-Hee Noh , Seung-Chul Lee , In-Joong Yoon , Hyun-Soo Kim , Shien-Young Kang , Young-Ki Choi , Changhee Lee
      Porcine reproductive and respiratory syndrome virus (PRRSV) is a globally ubiquitous swine virus that exhibits genetic and pathogenic heterogeneity among isolates. The present study was conducted to determine the complete genome sequence and pathogenicity of two Korean type 2 PRRSV nonstructural protein 2 (nsp2) deletion mutants, CA-2 and KNU-12-KJ4. The full-length genomes of CA-2 and KNU-12-KJ4 were determined to be 15,018 and 15,019 nucleotides in length, excluding the poly(A) tail, respectively, which were 393- or 392-nucleotide shorter than that of the type 2 NA prototype strain VR-2332 due to the presence of notable large deletions within the nsp2 gene. The genomes of CA-2 and KNU-12-KJ4 consisted of a 189- or 190-nucleotide 5′ untranslated region (UTR), a 14,677-nucleotide protein-coding region, and a 151-nucleotide 3′ UTR. Whole genome evaluation revealed that the nucleotide sequences of CA-2 and KNU-12-KJ4 are most similar to each other (10.7% sequence divergence), and then to the Korean strain CA-1 (11.3% sequence divergence) and the US strain MN184C (13.1% sequence divergence), respectively. To evaluate the in vitro immunity of nsp2 deletion variants, we sought to explore alteration of inflammatory cytokine and chemokine expression in PAM-pCD163 cells infected with each virus strain using quantitative real-time RT-PCR. Cytokine genes including IL-8, IL-10, and TNF-α, and chemokines such as MCP-1 and RANTES were found to be significantly elevated in nsp2 deletion virus-infected PAM cells. In contrast, expression of interferons (IFN-β, γ, and λ) and antiviral genes including ISG-15, -54, and -56 were unchanged or down-regulated in PAM cells infected with the nsp2 deletion mutants. Animal studies to assess the pathogenicity of nsp2 deletion PRRSVs demonstrated that both CA-2 and KNU-12-KJ4 strains notably produce weight loss in infected pigs. Furthermore, the nsp2 deletion mutants replicated well in pigs with significantly increased and prolonged viremia kinetics. Taken together, our results indicate that, among the three isolates, the outcome of in vitro and in vivo infection by CA-2 and KNU-12-KJ4 is comparable, suggesting that the large nsp2 deletion may be one of the viral genetic determinants contributing to PRRSV pathogenicity.


      PubDate: 2014-04-12T15:27:23Z
       
  • Laboratory diagnosis and transmissibility of bovine viral diarrhea virus
           from a bull with a persistent testicular infection
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Benjamin W. Newcomer , Kathy Toohey-Kurth , Yan Zhang , Bruce W. Brodersen , M. Shonda Marley , Kellye S. Joiner , Yijing Zhang , Patricia K. Galik , Kay P. Riddell , M. Daniel Givens
      Recently, in the United States, a dairy bull was diagnosed as the second confirmed case of persistent testicular infection (PTI) with bovine viral diarrhea virus (BVDV). The first objective of this study was to evaluate the testing methodologies currently used by the artificial insemination industry in order to improve the detection of bulls with PTI. This study evaluated the impact of multiple factors ([1] sample tested, [2] sample handling, [3] assay used, and [4] assay methodology) on the sensitivity of detection of BVDV. The second objective of this study was to evaluate the transmissibility of BVDV from the bull through casual or sexual contact. Results from this study indicate that straws of semen should be transported to the diagnostic laboratory in liquid nitrogen dry shippers. PCR proved to be a more sensitive assay than virus isolation; however, certain PCR protocols exhibited greater diagnostic sensitivity than others. Insemination with cryopreserved semen from this infected bull caused viral transmission to a seronegative heifer resulting in viremia and seroconversion. After 42 months of age, the bull appeared to clear the infection. In conclusion, this bull validates that natural exposure to a 1a strain of BVDV can result in a unique PTI causing contamination of semen with detectable infectious virus. Appropriate handling and testing of samples is necessary in order to detect bulls exhibiting PTI. Additionally, PTI with BVDV may potentially be cleared after an extended duration.


      PubDate: 2014-04-12T15:27:23Z
       
  • The prevalence and genetic diversity of group A rotaviruses on pig farms
           in the Mekong Delta region of Vietnam
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Pham Hong Anh , Juan J. Carrique-Mas , Nguyen Van Cuong , Ngo Thi Hoa , Nguyet Lam Anh , Do Tien Duy , Vo Be Hien , Phan Vu Tra My , Maia A. Rabaa , Jeremy Farrar , Stephen Baker , Juliet E. Bryant
      Group A rotaviruses (ARoVs) are a common cause of severe diarrhea among children worldwide and the cause of approximately 45% of pediatric hospitalizations for acute diarrhea in Vietnam. ARoVs are known to cause significant economic losses to livestock producers by reducing growth performance and production efficiencies, however little is known about the implications of asymptomatic endemic circulation of ARoV. We aimed to determine the prevalence and predominant circulating genotypes of ARoVs on pig farms in a southern province of Vietnam. We found overall animal-level and farm-level prevalence of 32.7% (239/730) and 74% (77/104), respectively, and identified six different G types and 4 P types in various combinations (G2, G3, G4, G5, G9, G11 and P[6], P[13], P[23], and P[34]). There was no significant association between ARoV infection and clinical disease in pigs, suggesting that endemic asymptomatic circulation of ARoV may complicate rotavirus disease attribution during outbreaks of diarrhea in swine. Sequence analysis of the detected ARoVs suggested homology to recent human clinical cases and extensive genetic diversity. The epidemiological relevance of these findings for veterinary practitioners and to ongoing pediatric ARoV vaccine initiatives in Vietnam merits further study.


      PubDate: 2014-04-12T15:27:23Z
       
  • Phylogeny of Spanish swine influenza viruses isolated from respiratory
           disease outbreaks and evolution of swine influenza virus within an
           endemically infected farm
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Gerard E. Martín-Valls , Meritxell Simon-Grifé , Sander van Boheemen , Miranda de Graaf , Theo M. Bestebroer , Núria Busquets , Margarita Martín , Jordi Casal , Ron A.M. Fouchier , Enric Mateu
      In the present study, outbreaks of respiratory disease were investigated for the presence of swine influenza virus (SIV). In 14 cases the circulating SIV strains were isolated, fully sequenced and compared with other known SIVs. The viruses causing the outbreaks belonged to the H1N1 (including human pandemic H1N1), H3N2 and H1N2 subtypes. In 11/14 cases the phylogenetic analyses indicated the occurrence of probable reassortment events. In the second part of the study, the genetic evolution of H1N1 SIV was assessed in a longitudinal study in closed groups of pigs over six months. Sequencing of the 22 isolates indicated co-circulation of two different variants for the same virus, as well as the emergence of SIV reassortants at certain time-points. These results indicate that reassortment events in SIV are common, and point towards the need for a better understanding of the epidemiology of SIV, particularly in endemic farms.


      PubDate: 2014-04-12T15:27:23Z
       
  • Bighorn sheep×domestic sheep hybrids survive Mannheimia haemolytica
           challenge in the absence of vaccination
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): R. Subramaniam , S. Shanthalingam , J. Bavananthasivam , A. Kugadas , B. Raghavan , S.A. Batra , C.N. Herndon , J. Rodriguez , A. Tibary , D. Nelson , K.A. Potter , W.J. Foreyt , S. Srikumaran
      Bighorn sheep (BHS, Ovis canadensis) are much more susceptible than domestic sheep (DS, Ovis aries) to pneumonia caused by leukotoxin (Lkt)-producing members of the Family Pasteurellaceae, particularly Mannheimia haemolytica and Bibersteinia trehalosi. Leukotoxin is widely accepted as the critical virulence factor of these bacteria since Lkt-negative mutants do not cause death of BHS. Typically, DS carry Lkt-positive M. haemolytica and/or B. trehalosi as commensal bacteria in their nasopharynx. In contrast, most BHS do not carry Lkt-positive M. haemolytica or B. trehalosi, or carry Lkt-negative strains in their nasopharynx. In previous studies, we demonstrated that unimmunized DS resist M. haemolytica challenge while BHS succumb to it. We hypothesized that Lkt-neutralizing antibodies, induced by Lkt-positive M. haemolytica and/or B. trehalosi innately carried by DS in their nasopharynx, render them less susceptible to infection by these bacteria. In this study we developed BHS×DS F1 hybrids by artificial insemination of domestic ewes with BHS semen. F1 hybrids were fertile, and produced F2 hybrids and back-crosses. The F1, F2, and back-crosses were raised together with domestic ewes. All these animals acquired Lkt-positive M. haemolytica and/or B. trehalosi, and developed high titers of Lkt-neutralizing antibodies in the absence of vaccination. Furthermore, all of these animals resisted challenge with lethal dose of M. haemolytica. These results suggest that lack of previous exposure to Lkt is at least partially responsible for fatal pneumonia in BHS when they acquire Lkt-positive M. haemolytica and/or B. trehalosi from DS when the two species commingle.


      PubDate: 2014-04-12T15:27:23Z
       
  • Immune response of pigs to Salmonella enterica serovar Derby and
           Typhimurium infections
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Jan Matiasovic , Hana Stepanova , Hana Kudlackova , Hana Havlickova , Frantisek Sisak , Ivan Rychlik , Katarina Chlebova , Lenka Leva , Alena Osvaldova , Jan Gebauer , Martin Faldyna
      Interaction between pigs and Salmonella enterica serovar Derby (Salmonella Derby) is much less understood in comparison with Salmonella enterica serovar Typhimurium (Salmonella Typhimurium). To study interactions of weaned piglets with Salmonella Derby, we compared the course of infections with Salmonella Derby De1 and Salmonella Typhimurium DT104 strains, both isolated from pig herds with a long history of asymptomatic infection. Salmonella Derby strain used was shed during the 28-day experiment period, while Salmonella Typhimurium strain was not found in faeces after day 17 post-infection. When the piglets were co-infected with both strains, Salmonella Derby was present in faeces until the end of the experiment, whilst Salmonella Typhimurium disappeared after day 21 post-infection. At the end of the experiment, Salmonella Derby was present in more tissues when compared with Salmonella Typhimurium. Piglets infected with Salmonella Typhimurium responded earlier with synthesis of anti-lipopolysaccharide IgM and IgG antibodies and with higher antibody levels compared to piglets infected with Salmonella Derby. Cellular immune response to both strains was very low and was detected later than was the onset of IgG antibody production.


      PubDate: 2014-04-12T15:27:23Z
       
  • Rapid identification of differentially virulent genotypes of Paenibacillus
           larvae, the causative organism of American foulbrood of honey bees, by
           whole cell MALDI-TOF mass spectrometry
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Marc Oliver Schäfer , Elke Genersch , Anne Fünfhaus , Lena Poppinga , Noreen Formella , Barbara Bettin , Axel Karger
      Infection with Paenibacillus larvae, the etiological agent of American foulbrood, is lethal for honey bee larvae and may lead to loss of the entire colony. Of the four known ERIC-genotypes of P. larvae, ERIC I and II are most frequently observed and differ significantly in virulence. The course of the disease on the larval level is more accelerated after infection with genotype II strains allowing nurse bees to remove diseased larvae more efficiently before capping. For this reason the lead clinical symptom, conversion of capped larvae into ‘ropy mass’, is less frequently found than after infection with ERIC I strains bearing the risk of false negative diagnosis. In this study, the potential of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for the discrimination of P. larvae genotypes ERIC I and II was explored on the basis of a comprehensive set of isolates. Using commercial software and a reference database constructed from field and type strains, ERIC I and II genotypes of all field isolates could be unambiguously identified on basis of mass spectra. Statistical analysis showed that the genotype is the main determinant for the spectral phenotype and MS-based ERIC-type determination is robust against sample selection. Furthermore, analysis of samples from Canada and New Zealand showed that distribution of ERIC II is not restricted to Europe as previously assumed. We suggest adding ERIC I and II genotype isolates as type-specific reference spectra for use in routine diagnostics.


      PubDate: 2014-04-12T15:27:23Z
       
  • Introduction, expansion and coexistence of epidemic Flavobacterium
           psychrophilum lineages in Chilean fish farms
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Ruben Avendaño-Herrera , Armel Houel , Rute Irgang , Jean-François Bernardet , Marcos Godoy , Pierre Nicolas , Eric Duchaud
      Chile is one of the countries where the development of salmonid farming has been the most successful. The first importation of salmonids in Chile from the northern hemisphere dates back to the late 19th century and the country now ranks as the world second largest producer of farmed salmon. However, the fast increase of infections caused by the bacterium Flavobacterium psychrophilum is a growing concern for this local industry. This pathogen, also recognized as an important problem worldwide, has been first reported in Chile in 1993 and is currently affecting all three cultivated salmonid species: Atlantic salmon (Salmo salar), Coho salmon (Oncorhynchus kisutch) and rainbow trout (O. mykiss). Here we conducted a MLST (multi-locus sequence typing) analysis of the local genetic diversity of F. psychrophilum to better understand its origin and propagation in the country, and to suggest practices that could contribute to its control in the future. A total of 94 bacterial isolates, collected from the main production zones, were analyzed and compared to those of other origins already available. The data reveal the country-wide distribution of several genotypes closely related to those that are the most prevalent in European and North American fish farms, and overlapping host fish species of the different lineages. This population structure is probably the direct consequence of local fish farming practices that relied until recently on massive import of fish eggs (e.g., 78 million of eggs in 2012) and where mixed-species farms and fish transportation across the country are common.


      PubDate: 2014-04-12T15:27:23Z
       
  • Subtype analysis of Salmonella isolated from subclinically infected dairy
           cattle and dairy farm environments reveals the presence of both human- and
           bovine-associated subtypes
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): L.D. Rodriguez-Rivera , E.M. Wright , J.D. Siler , M. Elton , K.J. Cummings , L.D. Warnick , M. Wiedmann
      While it is well established that clinically ill livestock represent a reservoir of Salmonella, the importance of subclinical shedders as sources of human salmonellosis is less well defined. The aims of this study were to assess the subtype diversity of Salmonella in healthy dairy cattle and farm environments and to compare the subtypes isolated from these sources with the Salmonella subtypes associated with clinical human cases in the same geographic area. A total of 1349 Salmonella isolates from subclinical dairy cattle and farm environments (46 farms) were initially characterized by traditional or molecular serotyping and tested for antimicrobial susceptibility. A set of 381 representative isolates was selected for further characterization by pulsed-field gel electrophoresis (PFGE); these isolates represented unique combinations of sampling date, serovar, antimicrobial resistance pattern, farm of origin, and source, to avoid overrepresentation of subtypes that were re-isolated from a given source. These 381 isolates represented 26 Salmonella serovars; the most common serovars were Cerro [(38.8%, 148/381) isolated from 21 farms], Kentucky [16.3%; 10 farms], Typhimurium [9.4%; 7 farms], Newport [7.6%; 8 farms], and Anatum [6.3%; 6 farms]. Among the 381 isolates, 90 (23.6%) were resistant to between 1 and 11 antimicrobial agents, representing 50 different antimicrobial resistance patterns. Overall, 61 XbaI-PFGE types were detected among these 381 isolates, indicating considerable Salmonella diversity on dairy farms. Fourteen PFGE types, representing 12 serovars, exactly matched PFGE types from human isolates, suggesting that subclinically infected dairy cattle could be sources of human disease-associated Salmonella.


      PubDate: 2014-04-12T15:27:23Z
       
  • Microsatellite markers for direct genotyping of the crayfish plague
           pathogen Aphanomyces astaci (Oomycetes) from infected host tissues
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Frédéric Grandjean , Trude Vrålstad , Javier Diéguez-Uribeondo , Mišel Jelić , Joa Mangombi , Carine Delaunay , Lenka Filipová , Svetlana Rezinciuc , Eva Kozubíková-Balcarová , Daniel Guyonnet , Satu Viljamaa-Dirks , Adam Petrusek
      Aphanomyces astaci is an invasive pathogenic oomycete responsible for the crayfish plague, a disease that has devastated European freshwater crayfish. So far, five genotype groups of this pathogen have been identified by applying random amplified polymorphic DNA analysis on axenic cultures. To allow genotyping of A. astaci in host tissue samples, we have developed co-dominant microsatellite markers for this pathogen, tested them on pure cultures of all genotype groups, and subsequently evaluated their use on tissues of (1) natural A. astaci carriers, i.e., North American crayfish species, and (2) A. astaci-infected indigenous European species from crayfish plague outbreaks. Out of over 200 potential loci containing simple sequence repeat (SSR) motifs identified by 454 pyrosequencing of SSR-enriched library, we tested 25 loci with highest number of repeats, and finally selected nine that allow unambiguous separation of all known RAPD-defined genotype groups of A. astaci from axenic cultures. Using these markers, we were able to characterize A. astaci strains from DNA isolates from infected crayfish tissues when crayfish had a moderate to high agent level according to quantitative PCR analyses. The results support the hypothesis that different North American crayfish hosts carry different genotype groups of the pathogen, and confirm that multiple genotype groups, including the one originally introduced to Europe in the 19th century, cause crayfish plague outbreaks in Central Europe. So far undocumented A. astaci genotype seems to have caused one of the analysed outbreaks from the Czech Republic. The newly developed culture-independent approach allowing direct genotyping of this pathogen in both axenic cultures and mixed genome samples opens new possibilities in studies of crayfish plague pathogen distribution, diversity and epidemiology.


      PubDate: 2014-04-12T15:27:23Z
       
  • Novel Bartonella infection in northern and southern sea otters (Enhydra
           lutris kenyoni and Enhydra lutris nereis)
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Sebastian E. Carrasco , Bruno B. Chomel , Verena A. Gill , Rickie W. Kasten , Ricardo G. Maggi , Edward B. Breitschwerdt , Barbara A. Byrne , Kathleen A. Burek-Huntington , Melissa A. Miller , Tracey Goldstein , Jonna A.K. Mazet
      Since 2002, vegetative valvular endocarditis (VVE), septicemia and meningoencephalitis have contributed to an Unusual Mortality Event (UME) of northern sea otters in southcentral Alaska. Streptococcal organisms were commonly isolated from vegetative lesions and organs from these sea otters. Bartonella infection has also been associated with bacteremia and VVE in terrestrial mammals, but little is known regarding its pathogenic significance in marine mammals. Our study evaluated whether Streptococcus bovis/equinus (SB/E) and Bartonella infections were associated with UME-related disease characterized by VVE and septicemia in Alaskan sea otter carcasses recovered 2004–2008. These bacteria were also evaluated in southern sea otters in California. Streptococcus bovis/equinus were cultured from 45% (23/51) of northern sea otter heart valves, and biochemical testing and sequencing identified these isolates as Streptococcus infantarius subsp. coli. One-third of sea otter hearts were co-infected with Bartonella spp. Our analysis demonstrated that SB/E was strongly associated with UME-related disease in northern sea otters (P <0.001). While Bartonella infection was also detected in 45% (23/51) and 10% (3/30) of heart valves of northern and southern sea otters examined, respectively, it was not associated with disease. Phylogenetic analysis of the Bartonella ITS region allowed detection of two Bartonella species, one novel species closely related to Bartonella spp. JM-1, B. washoensis and Candidatus B. volans and another molecularly identical to B. henselae. Our findings help to elucidate the role of pathogens in northern sea otter mortalities during this UME and suggested that Bartonella spp. is common in sea otters from Alaska and California.


      PubDate: 2014-04-12T15:27:23Z
       
  • MLST typing of Pasteurella multocida associated with haemorrhagic
           septicaemia and development of a real-time PCR specific for haemorrhagic
           septicaemia associated isolates
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Andreas Petersen , Magne Bisgaard , Kirsty Townsend , Henrik Christensen
      Two serovars of Pasteurella multocida, B:2 and E:2, have been reportedly associated with haemorrhagic septicaemia (HS), a peracute and devastating disease mainly affecting cattle and water buffaloes. We multilocus sequence typed (MLST) 64 isolates of P. multocida including 55 associated with HS and found that they mainly included sequence type (ST) 122 (n =50) and rarely ST63 (n =1), ST147 (n =2) and ST162 (n =2) compared to other members of the species isolated from other lesion types and hosts. Single-nucleotide polymorphisms suitable for specific detection of STs associated with HS were detected in the est gene. A new HS-est-RT-PCR (est indicating the target gene) specifically detected ST122, ST63, ST147 and ST162 associated with HS. The new HS-est-RT-PCR did not detect strains of ST151 with capsular type D isolated from pigs that were found positive with a previously published HS PCR detection method. The new HS-est-RT-PCR represents a fast and specific detection of the specific types of P. multocida involved in HS. The HS-est-RT-PCR developed in the current study seems to more accurately identify isolates of P. multocida associated with HS compared to PCR detection methods previously published.


      PubDate: 2014-04-12T15:27:23Z
       
  • Strategic use of serology for the diagnosis of bovine tuberculosis after
           intradermal skin testing
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Carmen Casal , Alberto Díez-Guerrier , Julio Álvarez , Sabrina Rodriguez-Campos , Ana Mateos , Richard Linscott , Edmond Martel , John C. Lawrence , Clare Whelan , John Clarke , Amanda O’Brien , Lucas Domínguez , Alicia Aranaz
      Diagnostic tests based on cell-mediated immunity are used in programmes for eradication of bovine tuberculosis (Mycobacterium bovis). Serological assays could be applied as ancillary methods to detect infected animals. Our objective was to evaluate two serological techniques: M. bovis Ab Test (IDEXX, USA) and Enferplex™ TB assay (Enfer, Ireland) in animals tested simultaneously with the single and comparative intradermal tests and the interferon-gamma assay. This work was performed at two stages. First, a preliminary panel of samples collected prior to intradermal tests from tuberculosis-free (n =60) and M. bovis-infected herds (n =78) was assayed, obtaining high specificity: 100% (M. bovis Ab Test) and 98.3% (Enferplex TB assay) but low sensitivity (detection of M. bovis infected animals): 23.9% (M. bovis Ab Test) and 32.6% (Enferplex TB assay). Subsequently, the use of serological techniques was further studied in two herds with M. bovis infection (n =77) using samples collected prior to, and 72h and 15 days after PPD inoculation. The highest level of detection of infected animals for serology was achieved at 15 days post-intradermal tests taking advantage of the anamnestic effect: 70.4% and 85.2% in herd A, and 66.7% and 83.3% in herd B, using M. bovis Ab Test and Enferplex TB assay, respectively. Quantitative results (average values obtained with M. bovis Ab Test ELISA and degree of positivity obtained with Enferplex TB assay) were higher in animals showing lesions compatible with tuberculosis. No significant differences were observed in the number of confirmed infected animals detected with either serological technique.


      PubDate: 2014-04-12T15:27:23Z
       
  • First report of multiresistance gene cfr in Enterococcus species
           casseliflavus and gallinarum of swine origin
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Yang Liu , Yang Wang , Lei Dai , Congming Wu , Jianzhong Shen
      The aim of this study was to investigate the presence and genetic environment of the multiresistance gene cfr in Enterococcus species of swine origin. Twenty-five cfr-carrying Enterococcus isolates were collected from swine in Beijing, Guangzhou, and Shandong, China. The isolates consist of 24 Enterococcus casseliflavus and one Enterococcus gallinarum isolate, and exhibited six SmaI PFGE patterns. The cfr gene was located on plasmids in all isolates except E. casseliflavus En83, in which cfr was located on the chromosomal DNA. The cfr gene environments in most of these isolates contain DNA sequences similar to pEF-01, which was first found in Enterococcus. However, inverse PCR analysis suggested that the cfr-carrying circular forms might be different from pEF-01. The circular forms in Eg51 and its transconjugant, and En23, En10, and En94 are similar to the circular form in pEF-01, except for the truncated IS1216, which is replaced by a transposase of the IS256 family in En24. The cfr circular form could not be detected in either En77 or En83, and the same cfr-carrying segments of ∼10kb had only 3500bp of sequence similar to pEF-01. This is the first report of cfr gene in E. casseliflavus and E. gallinarum. The potential dissemination of the multidrug resistance gene amongst different bacterial species, especially in enterococci of human and animal origins, is concerning and should be closely monitored.


      PubDate: 2014-04-12T15:27:23Z
       
  • Immunogenicity of Staphylococcus aureus LukM/F′-PV recombinant
           subunits: Validation of diagnostic potential and evaluation of protective
           efficacy in vitro
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): R.J. Padmaja , P.M. Halami
      Leukotoxin M/F′-Panton Valentine (LukM/F′-PV), a beta pore-forming toxin secreted by Staphylococcus aureus, is a major virulence factor involved in the pathogenesis of bovine mastitis. The present study was aimed to determine immunogenicity of two recombinant subunits of LukM/F′-PV, rLukM (MW 38kDa) and rLukF (MW 39kDa), develop and validate an indirect enzyme linked immunosorbent assay (ELISA) using polyclonal antibodies raised in rabbits, and evaluate applicability of the assay to diagnose clinical and subclinical bovine mastitis. Additionally, in vitro assays were conducted to determine abilities of antibodies to neutralize cytotoxicity of the native leukotoxin. A total of 87 bovine milk samples (healthy, subclinical and clinical mastitis) were evaluated for the presence of toxin determinants. Receiver–operator characteristic curve for the experimental ELISA values statistically interpreted a cut-off score of >0.109 OD405, with an assay specificity of 100% and sensitivity in the range of 80–87.5%. In addition, area under curve of 0.93–0.98 revealed the test was accurate in categorizing samples from infected and non-infected bovine. The rLukF IgG-ELISA was more sensitive than rLukM IgG-ELISA. Furthermore, it was evident from MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium) dye reduction, indirect immunofluorescence and lactate dehydrogenase assays that anti-rLukM/rLukF antibodies, with high neutralizing titers, inhibited in vitro leukotoxic activity and protected bovine neutrophil membrane integrity from cytotoxicity of native leukotoxin. The findings demonstrated that antibodies produced from recombinant subunits contribute to specific and sensitive immunodiagnosis and may also have the potential to provide passive therapeutic benefit in the management of bovine mastitis.


      PubDate: 2014-04-12T15:27:23Z
       
  • Variations in virulence of avian pathogenic Escherichia coli demonstrated
           by the use of a new in vivo infection model
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Susanne Elisabeth Pors , Rikke Heidemann Olsen , Jens Peter Christensen
      Salpingitis and peritonitis are common pathological manifestations observed in egg-laying hens. To improve methods to study these conditions, a surgical model was developed. Initially, eighteen white layers underwent laparotomy with subsequent inoculation of ink, bacteria or sterile broth directly into the oviduct. Eight birds inoculated with 0.1ml blue ink were euthanized immediately after inoculation and the specific site of inoculation was assessed. In all birds, ink was injected into the oviduct between five and seven cm cranial to the isthmus. To demonstrate the use of this approach to cause infection of the oviduct, five birds were inoculated with 8.6×106 CFU of a clinical Escherichia coli isolate. Five control birds received broth with no bacteria. Both infected and control birds were euthanized after 48h followed by a post mortem examination. Infected birds showed diffuse fibrino-purulent peritonitis, E. coli was found in pure culture from one or more positions in the oviduct and the liver. Birds receiving sterile broth did not culture positive and demonstrated no gross lesions. Subsequently, 19 birds were inoculated with an isolate of E. coli ST95 and 20 birds with an isolate of E. coli ST141. Major variation in virulence was observed between the two isolates used in relation to clinical signs, gross lesions and histopathology. In contrast to E. coli ST141, E. coli ST95 caused severe clinical signs, epithelial necrosis of the oviduct and purulent salpingitis. The results of the study show the potential of the model in studies of the pathogenesis of infections and virulence of bacteria of the oviduct.


      PubDate: 2014-04-12T15:27:23Z
       
  • Cross-infection of virulent Dichelobacter nodosus between sheep and
           co-grazing cattle
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Maren Knappe-Poindecker , Marianne Gilhuus , Tim K. Jensen , Synnøve Vatn , Hannah J. Jørgensen , Terje Fjeldaas
      Dichelobacter nodosus is the main aetiological agent of ovine footrot and the bacterium has also been associated with interdigital dermatitis is cattle. The aim of this study was to investigate possible cross-infection of virulent D. nodosus between sheep and co-grazing cattle. Five farms, where sheep previously diagnosed with virulent D. nodosus were co-grazing with cattle for different periods of time, were included. The study sample consisted of 200 cows and 50 sheep. All cows were examined for the presence of interdigital dermatitis, and ten ewes, preferably with symptoms of footrot, had the footrot scores recorded. On each farm, the same ten ewes and ten cows were chosen for bacterial analyses. Swabs were analysed for D. nodosus by PCR and culturing. D. nodosus isolates were virulence-tested and assigned to serogroups by fimA variant determination. Biopsies were evaluated histopathologically and analysed by fluorescent in situ hybridization for D. nodosus, Treponema spp. and Fusobacterium necrophorum. D. nodosus defined as virulent by the gelatin gel test were isolated from 16 sheep from four farms and from five cows from two of the same farms. All five cows had interdigital dermatitis. Two of the cows stayed infected for at least eight months. By pulsed-field gel electrophoresis (PFGE), the isolates from the five cows were found to be genetically indistinguishable or closely related to isolates from sheep from the same farm. This indicates that cross-infection between sheep and cows have occurred.


      PubDate: 2014-04-12T15:27:23Z
       
  • Epizootic haemorrhagic disease virus in Reunion Island: Evidence for the
           circulation of a new serotype and associated risk factors
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Catherine Cêtre-Sossah , Matthieu Roger , Corinne Sailleau , Lorène Rieau , Stephan Zientara , Emmanuel Bréard , Cyril Viarouge , Marina Beral , Olivier Esnault , Eric Cardinale
      Bluetongue virus (BTV) and epizootic haemorrhagic disease virus (EHDV) are members of the Orbivirus genus of the Reoviridae family transmitted between ruminants by the bites of Culicoides midges. BTV went undetected in Reunion Island between its first documented emergence in 1979 and two other serious outbreaks with both BTV-3 and EHDV-6 in 2003, and both EHDV-6 and BTV-2 in 2009. In these outbreaks, infected animals developed symptoms including hyperthermia, anorexia, congestion, prostration and nasal discharge. Samples were collected in 2011 to assess the prevalence of BT and EHD in ruminants native to Reunion Island by serological analysis. A cross-sectional study was undertaken on 67 farms, including a total of 276 cattle, 142 sheep and 71 goats. The prevalence rates of BT and EHD were 58% (95% CI [54.03–62.94]) and 38% (95% CI [33.85–42.63], respectively. Two further suspected outbreaks were confirmed to involve EHDV and BTV/EHDV. A new circulating EHDV serotype 1 of unknown origin was isolated. Our results confirm that the prevalence of both BT and EHD is high and that both are likely currently circulating. A high risk of BTV and EHDV infections was associated with the introduction of ruminants from neighbouring farms without quarantine, the presence of organic and other waste on the farm, and treatment against ectoparasites and insects.


      PubDate: 2014-04-12T15:27:23Z
       
  • Preliminary characterisation of Pentlands paramyxovirus-1, -2 and -3,
           three new paramyxoviruses of rodents
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Fiona Brooks , Ann R. Wood , Jackie Thomson , David Deane , David J. Everest , Colin J. McInnes
      A paramyxovirus was discovered by chance during the primary culture of grey squirrel (Sciurus carolinensis) kidney cells from the UK. Amplification, sequencing and phylogenetic analysis of part of the genome encoding a region of the RNA polymerase (L gene) confirmed that the virus was a member of the Paramyxovirinae subfamily, but that it did not partition with any of the currently recognised paramyxovirus genera and instead segregated with the unclassified rodent viruses, J-virus, Beilong virus and Tailam virus as well as paramyxoviruses recently detected in rodents in Africa. A subsequent examination of kidney samples from red squirrels (Sciurus vulgaris) revealed that they too harboured a paramyxovirus, but sequence analysis of the corresponding region of the L gene revealed that it was approximately 67% identical to the grey squirrel virus, suggesting the presence of a second species of virus. In addition, one of the red squirrels examined harboured a second virus with approximately 69% identity to the grey squirrel virus, but only approximately 63% identity to the other red squirrel viruses, signifying the presence of a third species of paramyxovirus. In a sample of 22 red and grey squirrels 68% of those examined were found to harbour virus suggesting that paramyxovirus infection in squirrels may be common within the UK.


      PubDate: 2014-04-12T15:27:23Z
       
  • Experimental Schmallenberg virus infection of pigs
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Antoine Poskin , Willem Van Campe , Laurent Mostin , Brigitte Cay , Nick De Regge
      Schmallenberg virus (SBV) is a newly emerged virus responsible for an acute non-specific syndrome in adult cattle including high fever, decrease in milk production and severe diarrhea. It also causes reproductive problems in cattle, sheep and goat including abortions, stillbirths and malformations. The role of pigs in the epidemiology of SBV has not yet been evaluated while this could be interesting seen their suggested role in the epidemiology of the closely related Akabane virus. To address this issue, four 12 week old seronegative piglets were subcutaneously infected with 1ml of SBV infectious serum (FLI) and kept into contact with four non-infected piglets to examine direct virus transmission. Throughout the experiment blood, swabs and feces samples were collected and upon euthanasia at 28dpi different organs (cerebrum, cerebellum, brain stem, lung, liver, iliac lymph nodes, kidney and spleen) were sampled. No clinical impact was observed and all collected samples tested negative for SBV in rRT-PCR. Despite the absence of viremia and virus transmission, low and short lasting amounts of neutralizing antibodies were found in 2 out of 4 infected piglets. The limited impact of SBV infection in pigs was further supported by the absence of neutralizing anti-SBV antibodies in field collected sera from indoor housed domestic pigs (n =106). In conclusion, SBV infection of pigs can induce seroconversion but is ineffective in terms of virus replication and transmission indicating that pigs have no obvious role in the SBV epidemiology.


      PubDate: 2014-04-12T15:27:23Z
       
  • First report of a new alphaherpesvirus in a freshwater turtle (Pseudemys
           concinna concinna) kept in Germany
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Nicole Jungwirth , Rogier Bodewes , Albert D.M.E. Osterhaus , Wolfgang Baumgärtner , Peter Wohlsein
      Herpesviruses represent important pathogenic agents in zoological chelonian collections. Infections in tortoises are actually most commonly associated with necrotizing lesions in the upper digestive tract. Herpesvirus infections in sea turtles are most commonly associated with fibropapillomatosis, although other disease complexes caused by other herpesviruses have been described. Herpesviruses are known to cause latent infections and may be reactivated upon various endogenous or exogenous stimuli resulting in acute and sometimes fatal disease. The present description represents the first report about a new alphaherpesvirus found in a fresh water turtle (Pseudemys concinna concinna). The animal died suddenly without showing clinical signs. Macroscopically, no lesions typically associated with a herpesvirus infection were found. Light microscopic examination showed hepatic lipidosis and countless numbers of intranuclear inclusion bodies in hepatocytes as the only significant light microscopic lesion. Transmission electron microscopy revealed typical herpesvirus particles in the nucleus of hepatocytes. To further substantiate these observations a molecular identification using PCR followed by sequencing of the obtained fragments was performed. Phylogenetic analysis indicated a new alphaherpesvirus called Emydid herpesvirus 1.


      PubDate: 2014-04-12T15:27:23Z
       
  • Caspian White Fish (Rutilus frisii kutum) as a host for Spring Viraemia of
           Carp Virus
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): M. Ghasemi , H. Zamani , S.M. Hosseini , S. Haghighi Karsidani , S.M. Bergmann
      Rutilus frisii kutum is a fish of the Cyprinidae Family which is native in Caspian Sea and commercially cultured in Iran. This study was conducted to investigate susceptibility of Caspian White Fish to Spring Viraemia of Carp Virus (SVCV) infection and to evaluate influence of different challenge routes on virulence of the virus. Fingerlings were infected by immersion, intra-peritoneal (i.p.) injection, cohabitation and orally. Dead and surviving fish were collected for histological examination as well as for virus re-isolation by cell culture, Reverse Transcriptase Polymerization Chain Reaction (RT-PCR) and Indirect Fluorescent Antibody Test (IFAT) analysis. The results indicated that immersion was the best infectious route of transmission with the highest mortality, whereas oral transmission showed the lowest mortality. The virus was also re-isolated from dead fish and identified by IFAT. In addition, histopathological changes including branchial, hepatic and splenic necrosis as well as glomerulonephritis and necrosis in kidney were observed in diseased fish tissues but not in the survivors. RT-PCR on samples obtained from surviving fish tissues detected viral genome in the fish surviving from immersion, i.p. injection and cohabitation challenges but not in the fish infected orally. In conclusion, Caspian White Fish are susceptible to infection by SVCV and virulence of the virus could be influenced by route of transmission. In addition, SVCV could persist in surviving fish, which may serve as reservoirs of the virus, transmitting infection to healthy fish population.


      PubDate: 2014-04-12T15:27:23Z
       
  • Interspecies transmission of canine influenza virus H5N2 to cats and
           chickens by close contact with experimentally infected dogs
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Feng Hai-xia , Liu Yuan-yuan , Song Qian-qian , Ling Zong-shuai , Zhang Feng-xia , Zhu Yan-li , Jiang Shi-jin , Xie Zhi-jing
      The novel H5N2 influenza virus, CA/SD/JT01/09, was isolated from the dog exhibiting respiratory signs in China in 2009. Dog to dog transmission of the novel H5N2 was previously confirmed. But interspecies transmission of the virus between dogs and the other animals has still remained unclear. To determine whether the virus can be transmitted directly from dogs to cats and chickens, we conducted contact exposure experiments. Susceptible cats and chickens were housed in the room which the novel H5N2 infected dogs were housed in, respectively. As a result, only one cat showed clear manifestations of H5N2 infection, but susceptibility of the other cats to H5N2 was confirmed by seroconversion. Eight of the exposure chickens showed clear manifestations of illness and 2 chickens died, and it demonstrates that chickens are susceptible to the recombinant H5N2. It implied that close contact between the H5N2-infected dogs and the cats and chickens resulted in spread of the virus to the sentinel animals.


      PubDate: 2014-04-12T15:27:23Z
       
  • Is there a relation between genetic or social groups of mallard ducks and
           the circulation of low pathogenic avian influenza viruses'
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Maria A. De Marco , Alessio Valentini , Emanuela Foni , Maria C. Savarese , Claudia Cotti , Chiara Chiapponi , Elisabetta Raffini , Isabella Donatelli , Mauro Delogu
      We investigated the circulation dynamics of low pathogenic avian influenza viruses (LPAIVs) in the mallard (Anas platyrhynchos) reservoir in Italy. In particular, we evaluated the temporal distribution of virologic findings by combining virus isolation data with a new population genetic-based study approach. Thus, during 11 consecutive sampling periods (wintering periods between 1993/94 and 2003/04), categorised into 40 sampling sub-periods, cloacal swab samples were collected from 996 wild and 16 captive-reared mallards, to be screened by RT-PCR before attempting influenza A virus isolation in embryonated eggs. Forty-eight LPAIVs were isolated from wild mallards and antigenically characterised by haemagglutination-inhibition and neuraminidase-inhibition assays. When considering LPAIV antigenic subtypes in which more than one mallard tested virus isolation positive (H1N1, n. 22; H2N3, n. 2; H5N3, n. 2; H6N5, n. 3; H6N8, n. 2; H7N3, n. 3; H11N6, n. 5), at least two birds infected with a specific HN subtype clustered within one same sampling sub-period. In the context of the novel population genetic approach, total DNA was extracted from a subset of 16 captive-reared and 65 wild ducks (2000/01 and 2001/02 sampling periods) to assess genetic diversity by amplified fragment length polymorphisms (AFLP) markers. Analyses of AFLP results showed that captive-reared mallards clustered together, whereas two main independent clusters characterised the distribution pattern of most wild mallards. Within this subset of samples, nearly identical H7N3 LPAIV strains were isolated from two wild mallards belonging to the same genetic cluster. Blood sera were also collected from the above subset of mallards and examined for antibodies to the homologous H7N3 virus strain. Four out of six wild mallards testing H7N3-seropositive by haemagglutination-inhibition assay (2001/02 period) belonged to the genetic cluster including H7N3 virus shedding ducks. Overall, our data raise the possibility of an enhanced transmission and circulation of LPAIVs in genetic or social groups of wild mallards, gathered in flocks possibly related by parentage and/or geographic origin.


      PubDate: 2014-04-12T15:27:23Z
       
  • Novel rope-based sampling of classical swine fever shedding in a group of
           wild boar showing low contagiosity upon experimental infection with a
           classical swine fever field strain of genotype 2.3
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Susan Mouchantat , Anja Globig , Wolfgang Böhle , Anja Petrov , Heinz-Günther Strebelow , Thomas C. Mettenleiter , Klaus Depner
      Several classical swine fever (CSF) epidemics in wild boar and domestic pigs in Europe during the last decades have been caused by CSF virus (CSFV) strains of genotype 2.3. This genotype is known to be virulent leading to high morbidity and mortality. We experimentally infected two eight months old wild boar with 105,5 TCID50 of CSFV genotype 2.3 and kept the animals together with five noninoculated wild boar of the same age. Our original purpose was to evaluate a non-invasive sampling method based on saliva collection using “rope-in-a-bait” sampling baits. While expecting high morbidity, high level of virus shedding and some mortality, we actually observed a subclinical course of infection with an unexpected low contagiosity. The two inoculated animals infected only three contact animals while two contact animals remained uninfected. These findings substantially add to our epidemiological understanding of CSFV circulation in wild boar populations. CSFV infected animals older than six months and in good condition may not shed sufficient virus to transmit infection to all seronegative in-contact animals. The contagiosity in relation to the animal's age is discussed. This supports the hypothesis of silent perpetuation of CSFV in wild boar populations for several months if the wild boar density is sufficiently high. The feasibility of the “rope-in-a-bait” sampling method could be proven during the short viraemic phase of infected animals during the second week of infection.


      PubDate: 2014-04-12T15:27:23Z
       
  • Time course Haemophilus parasuis infection reveals pathological
           differences between virulent and non-virulent strains in the respiratory
           tract
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Bernardo Bello-Orti , Mar Costa-Hurtado , Veronica Martinez-Moliner , Joaquim Segalés , Virginia Aragon
      Haemophilus parasuis is a common inhabitant of the upper respiratory tract of pigs and the etiological agent of Glässer's disease. However, the host–pathogen interaction remains to be well understood. In this work, 33 colostrum-deprived pigs were divided in 4 groups and each group was inoculated intranasally with a different H. parasuis strain (non-virulent strains SW114 and F9, and virulent strains Nagasaki and IT29755). Animals were necropsied at different times in order to determine the location of the bacteria in the respiratory tract of the host during infection. An immunohistochemistry method was developed to detect H. parasuis in nasal turbinates, trachea and lung. Also, the co-localization of H. parasuis with macrophages or neutrophils was examined by double immunohistochemistry and double immunofluorescence. Virulent strains showed a biofilm-like growth in nasal turbinates and trachea and were found easily in lung. Some virulent bacteria were detected in association with macrophages and neutrophils, but also inside pneumocyte-like cells. On the other hand, non-virulent strains were seldom detected in nasal turbinates and trachea, where they showed a microcolony pattern. Non-virulent strains were essentially not detected in lung. In conclusion, this work presents data showing differential localization of H. parasuis bacteria depending on their virulence. Interestingly, the intracellular location of virulent H. parasuis bacteria in non-phagocytic cells in lung could allow the persistence of the bacteria and constitute a virulence mechanism.


      PubDate: 2014-04-12T15:27:23Z
       
  • Effects of fluoroquinolone treatment and group housing of pigs on the
           selection and spread of fluoroquinolone-resistant Campylobacter
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Masaru Usui , Yoko Sakemi , Ikuo Uchida , Yutaka Tamura
      There are concerns that the use of fluoroquinolones (FQs) and group housing of food animals may contribute to the development of bacterial FQ resistance. Here, we studied the effects of administering FQ to pigs on the selection of FQ-resistant Campylobacter. Fifteen pigs were randomly allocated to either a group treated with FQs (enrofloxacin or norfloxacin), or an untreated control group. The number of FQ-resistant Campylobacter in feces was determined using appropriate selective agar containing enrofloxacin. FQ-resistant Campylobacter from samples of both groups were observed on days 3 and 4. These bacteria persisted for up to 21 days after treatment was discontinued. To evaluate the effect of group housing on the transmission of FQ-resistant Campylobacter, five pigs infected with FQ-sensitive Campylobacter pigs and one pig infected with FQ-resistant Campylobacter were housed together. On day 3, FQ-resistant Campylobacter were isolated from all six pigs. Moreover, FQ-resistant Campylobacter were isolated from environmental samples from the pen. These results indicate that the treatment of pigs with FQs selects for and spreads FQ-resistant Campylobacter among the pen. Therefore, responsible and prudent use of FQs at pig farms is required to prevent the emergence and transmission of FQ-resistant Campylobacter.


      PubDate: 2014-04-12T15:27:23Z
       
  • Brucella suis in armadillos (Chaetophractus villosus) from La Pampa,
           Argentina
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Marta S. Kin , Marcelo Fort , Susana T. de Echaide , Emma B. Casanave
      Brucellosis is a zoonotic disease transmitted from an animal reservoir to humans. Both, wildlife and domestic animals, contribute to the spreading of these zoonosis. The surveillance of the animal health status is strictly regulated for domestic animals, whereas disease monitoring in wildlife does not exist. The aim of the present study was to provide data on the prevalence of anti-Brucella antibodies in Chaetophractus villosus from a region of La Pampa, Argentina to assess public health risks. The C. villosus is endemic to South America, and in Argentina it represents a food resource for human consumption. A total of 150 sera of armadillos bleeding between 2007 and 2010 were tested using buffered plate antigen test (BPAT), serum agglutination test (SAT), 2-mercaptoethanol (2-ME) and complement fixation test (CFT), for the detection of anti-Brucella antibodies. Antibodies to Brucella sp. were found in 16% (24:150) of the armadillos tested using the BPAT test. All 24 positive samples were confirmed by the SAT, 2-ME and CFT tests. Strain isolation was attempted from liver and spleen samples of two animals with positive serology. Isolates were characterized by conventional biotyping and identification of specific DNA using polymerase chain reaction (PCR). A total of 2 isolates were recovered from spleen and liver. Both of them were identified as Brucella suis biovar 1. This preliminary study provides the first report on the seroprevalence of brucellosis and describes the first isolate of B. suis biovar 1 in C. villosus in Argentina.


      PubDate: 2014-04-12T15:27:23Z
       
  • High prevalence of closely-related Acinetobacter baumannii in pets
           according to a multicentre study in veterinary clinics, Reunion Island
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): O. Belmonte , H. Pailhoriès , M. Kempf , M.P. Gaultier , C. Lemarié , C. Ramont , M.L. Joly-Guillou , M. Eveillard
      Our objective was to study the carriage of Acinetobacter baumannii (AB) in pets in Reunion Island (RI), a French territory in Indian Ocean. Overall, 138 pets were sampled (rectum, mouth, wounds if applicable) in 9 veterinary clinics (VC). The prevalence of AB carriage was 6.5% (95%CI; 2.4, 10.6) and 9 carriers were indentified from 4 VC. Hospitalization in a VC and antimicrobial treatment administered within the 15 preceding days were significantly associated with AB carriage (P <0.01 and P <0.05, respectively). Despite the VC in which animals have been sampled were located all around RI, most isolates (8/9) were closely-related (>90% similarity by pulsed-field gel electrophoresis). Additional studies are needed to improve the understanding about interactions between the different reservoirs of AB in RI.


      PubDate: 2014-04-12T15:27:23Z
       
  • Extradural spinal cord lesion in a dog: First case study of canine
           neurological histoplasmosis in Italy
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): A. Reginato , P. Giannuzzi , M. Ricciardi , A. De Simone , M. Sanguinetti , I. Porcellato , M.T. Mandara
      A 7-year-old intact male mixed dog was presented with a history of acute and progressive paraparesis. Abnormal clinical signs consisted of non-ambulatory paraparesis, hind limbs hypertonia and severe thoracolumbar pain. Magnetic resonance imaging demonstrated an isointense in T1 and T2 WI epidural lesion, with good contrast enhancement, extending from T-10 to T-13. Laminectomy was carried out to remove the epidural mass. Histological examination revealed a pyogranulomatous lesion characterized by numerous macrophages containing yeast-like Grocott and PAS-positive bodies. Immunohistochemistry and PCR performed on formalin-fixed paraffin-embedded tissue confirmed Histoplasma capsulatum as the causative agent. H. capsulatum has a worldwide distribution in temperate and subtropical climates but its presence as an autochthonous fungus in Europe is now recognized. To the authors’ knowledge this is the first report of canine histoplasmosis in Italy with lesion confined to the central nervous system.


      PubDate: 2014-04-12T15:27:23Z
       
  • The identification, typing, and antimicrobial susceptibility of
           Pseudomonas aeruginosa isolated from mink with hemorrhagic pneumonia
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Jing Qi , Lulu Li , Yijun Du , Shourong Wang , Jinwen Wang , Yanbo Luo , Jie Che , Jinxing Lu , Hui Liu , Guangchun Hu , Jixia Li , Yanwen Gong , Guisheng Wang , Ming Hu , ShiganYan , Yuqing Liu
      The biological characteristics and molecular epidemiology of Pseudomonas aeruginosa associated with mink hemorrhagic pneumonia from Shandong province of eastern China were determined in this study. From 2010 to 2011, 30 mink P. aeruginosa isolates were identified from lung, fecal and feed samples of clinical cases and subjected to serotyping, antimicrobial susceptibility testing and pulsed-field gel electrophoresis (PFGE) using SpeI. The P. aeruginosa isolates belonged to four serotypes—21 of type G, four of type I, three of type M, one of type B, and one non-typable strain. The strains were divided into four large groups as determined by PFGE. Isolates from the group 2 were highly homologous and were obtained from the same region as an epidemic. All of the isolates were sensitive to piperacillin, piperacillin/tazobactam, ceftazidime, cefepime, imipenem, amikacin, gentamicin and tobramycin and resistant to ampicillin, cefuroxime and cefuroxime axetil. A high frequency of resistance was found to ampicillin/sulbactam, cefazolin, cefotetan, ceftriaxone, nitrofurantoin, and trimethoprim/sulfamethoxazole (96.7%). Resistance to ticarcillin/clavulanic acid, ciprofloxacin and levofloxacin was less common (13.3%). There was no relationship between antibiotic resistance and serotype distribution of the isolates. The epidemic serotype of P. aeruginosa from the mink hemorrhagic pneumonia in Shandong province was type G, which was a clone of commonly found in this province. These findings reveal the genetic similarities and antimicrobial susceptibility profiles of P. aeruginosa from clinical cases of mink hemorrhagic pneumonia and will facilitate the prevention and control of the disease in Shandong province of China.


      PubDate: 2014-04-12T15:27:23Z
       
  • Duck hepatitis A virus (DHAV) genotype definition: Comment on the article
           by Cha et al.
    • Abstract: Publication date: 4 June 2014
      Source:Veterinary Microbiology, Volume 170, Issues 3–4
      Author(s): Huiqiang Wen , Lingxia Han , Xiaona Zhang , Chuanjiang Lian , Lili Zhao , Changde Si , Hongyan Chen
      Duck hepatitis A virus (DHAV) is genetically divided into three different genotypes: the original type DHAV-1, a type recently isolated in Taiwan (DHAV-2), and a recently described type isolated in South Korea and China (DHAV-3). Recently, Cha et al. (2013) concluded that the existence that both DHAV-1 and DHAV-2 had been classified into one branch, with DHAV genotype 3 (DHAV-3) in another, and that the phylogenetic distance unit showed was 0.5, a tremendous value. However, there might be some concerns on the methodology application to define the genotypes of DHAV. Based on 110 genomic and 100 amino acid sequences of DHAV which included all the sequences from Cha et al. (2013) respectively, phylogenetic analysis in the present study showed a distinct and proposed DHAV genotype definition, that both DHAV-2 and DHAV-3 were clustered in one branch while DHAV-1 in another branch only, and that the phylogenetic distance unit of 0.02 was confirmed, which was much smaller than the value 0.5. Taking into account the genotype definition of DHAV, we also conducted the pairwise sequence comparisons (PASC) analysis of 110 genomic sequences, and proposed that the distance genotype definition threshold was 0.045.


      PubDate: 2014-04-12T15:27:23Z
       
  • The association between occurrence of plasmid-mediated quinolone
           resistance and ciprofloxacin resistance in Escherichia coli isolates of
           different origins
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Tong Yang , Zhenling Zeng , Lili Rao , Xiaojie Chen , Dandan He , Luchao Lv , Jing Wang , Li Zeng , Minsha Feng , Jian-Hua Liu
      This study was performed to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants and characterize the ciprofloxacin resistance in Escherichia coli isolated from different sources in China. PMQR determinants were detected by PCR amplification and sequencing in 2297 E. coli isolates randomly collected from animals, food and humans during 2004 to 2011. MICs of ciprofloxacin were determined by agar dilution method. Of the 2297 E. coli isolates, 43.6% harbored at least one PMQR gene. The most common PMQR gene was oqxAB (29.3%), followed by qnr (13.6%), aac(6′)-Ib-cr (11.6%), and qepA (3.3%). 12.0% isolates carried two or more PMQR genes. The prevalence of PMQR genes in food animal isolates increased over time, from 38.7% in 2004 to 69.8% in 2011. The prevalence of PMQR/ciprofloxacin resistance among isolates from pig, chicken, duck, companion animals, animal food and human volunteers were 65.2%/69.6%, 42.4%/60.0%, 59.4%/65.0%, 28.6%/57.5%, 29.3%/25.6%, and 14.0/8.7%, respectively. Most isolates carrying qnr along showed susceptible to ciprofloxacin, and only 21.6% the isolates exhibited resistance to ciprofloxacin, which was significantly lower than those carrying other PMQR genes (65.2–89.9%) and those that do not (43.1%) (p <0.01). In conclusion, high frequency of ciprofloxacin resistance and PMQR genes was observed among E. coli isolates of different origins in China, with oqxAB being the most frequent. qnr-positive E. coli isolates have relatively low ciprofloxacin resistance rate compared with other PMQR determinants-carrying isolates and PMQR-negative isolates.


      PubDate: 2014-03-17T10:06:10Z
       
  • Carriage of Staphylococcus species in the veterinary visiting dog
           population in mainland UK: Molecular characterisation of resistance and
           virulence
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Amy L. Wedley , Susan Dawson , Thomas W. Maddox , Karen P. Coyne , Gina L. Pinchbeck , Peter Clegg , Dorota Jamrozy , Mark D. Fielder , David Donovan , Tim Nuttall , Nicola J. Williams
      This study investigated the prevalence of nasal carriage of staphylococci in dogs and determined the characteristics of the isolates. A total of 724 dogs from 87 veterinary practices across the mainland UK were screened for carriage of Staphylococcus spp. All isolates were examined for meticillin resistance (MR) and the presence of the mecA gene investigated in those isolates showing resistance. All coagulase-positive staphylococci and MR coagulase-negative staphylococci (MRCoNS) were subjected to antimicrobial susceptibility testing. Spa typing and DNA microarray analysis of resistance and virulence genes was carried out on all MR S. aureus (MRSA) and a subset of meticillin susceptible S. aureus (MSSA). Staphylococci were isolated from 399 (55.1%) of the dogs; only seven (1%) carried MRSA, all of which were identified as the dominant UK healthcare-associated strain (EMRSA-15, ST22). MSSA was identified in 47 (6.5%) dogs, the sequence types of which have been suggested as precursors to successful MRSA clones. Forty (5.5%) dogs carried MRCoNS, while no dogs carried MR S. pseudintermedius, although this is increasingly reported in mainland Europe. Resistance to antimicrobials among the isolates varied between species, with multidrug resistance (MDR) in 87.5% of MRCoNS and 21.8% of coagulase positive staphylococci. Microarray analysis of MRSA and a subset of MSSA isolates identified numerous virulence genes associated with pathogenesis, which are commonly identified in isolates of human origin. However, no isolates carried Panton-Valentine leukocidin (PVL) genes. This study suggests that MRSA carriage is low in the vet visiting dog population, but there is a diverse range of virulence and resistance determinants in canine S. aureus and MRCoNS isolates.


      PubDate: 2014-03-17T10:06:10Z
       
  • Patterns of antimicrobial resistance in pathogenic Escherichia coli
           isolates from cases of calf enteritis during the spring-calving season
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): James F. Gibbons , Fiona Boland , James F. Buckley , Francis Butler , John Egan , Séamus Fanning , Bryan K. Markey , Finola C. Leonard
      Neonatal enteritis is a common condition of young calves and can be caused by pathogenic strains of Escherichia coli. We hypothesised that on-farm antimicrobial use would result in an increased frequency of resistance in these strains during the calving season. We also sought to determine if the frequency of resistance reflected on-farm antimicrobial use. Faecal samples were collected from cases of calf enteritis on 14 spring-calving dairy farms during two 3 week periods: Period 1 – February 11th through March 2nd 2008 and Period 2 – April 14th through May 5th 2008. E. coli were cultured from these samples, pathogenic strains were identified and antimicrobial susceptibility testing was carried out on these pathogenic isolates. Antimicrobial prescribing data were collected from each farm for the previous 12 months as an indicator of antimicrobial use. The correlation between antimicrobial use and resistance was assessed using Spearman's correlation coefficient. Logistic regression analysis was used to investigate the relationship between resistance, sampling period and pathotype. Penicillins and aminopenicillins, streptomycin, and tetracyclines were the most frequently prescribed antimicrobials and the greatest frequencies of resistance were detected to these 3 antimicrobial classes. A strong correlation (ρ =0.879) was observed between overall antimicrobial use and frequencies of antimicrobial resistance on farms. Sampling period was significant in the regression model for ampicillin resistance while pathotype was significant in the models for streptomycin, tetracycline and trimethoprim/sulphamethoxazole resistance. The frequencies of resistance observed have implications for veterinary therapeutics and prudent antimicrobial use. Resistance did not increase during the calving season and factors other than antimicrobial use, such as calf age and bacterial pathotype, may influence the occurrence of resistance in pathogenic E. coli.


      PubDate: 2014-03-17T10:06:10Z
       
  • Experimental salmonellosis challenge model in older calves
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Timothy A. Snider , Tamara Gull , Todd A. Jackson , Francisco J. Martinez-Becerra , Daniel R. Picking , William D. Picking , Wendy L. Picking
      Non-typhoidal Salmonella serovars (NTS) are the leading cause of foodborne illnesses worldwide and the leading cause of hospitalization and death due to foodborne illnesses in the United States. While there has been some progress in vaccine development against Salmonella spp., there are no broadly protective vaccines. A compounding factor in the development of these vaccines is the lack of a natural model. Most vaccine research is performed utilizing a mouse typhoid model. Unlike mice, calves infected with Salmonella develop gastroenteritis similar to the disease in humans. The initial step in developing a model of infection in older calves is the determination of a bacterial dose that elicits substantial clinical disease without causing death. Ten-week-old calves were orally inoculated with increasing doses of either Salmonella enterica serovar Typhimurium or Newport. Clinical illness scores were assigned based on rectal temperature, fecal consistency, attitude and hydration. Gross and microscopic pathology findings were also evaluated. These older calves exhibited clinical and pathologic signs of severe gastroenteritis without death losses with effective dose of 1×108CFUs for S. Typhimurium and 1×107CFUs for S. Newport.


      PubDate: 2014-03-17T10:06:10Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2




      PubDate: 2014-03-17T10:06:10Z
       
  • Infection of differentiated airway epithelial cells from caprine lungs by
           viruses of the bovine respiratory disease complex
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Jana Kirchhoff , Sabine Uhlenbruck , Günther M. Keil , Christel Schwegmann-Wessels , Martin Ganter , Georg Herrler
      Bovine respiratory syncytial virus (BRSV), bovine parainfluenza virus type 3 (BPIV3) and bovine herpesvirus type 1 (BHV-1) are important pathogens associated with the bovine respiratory disease complex (BRDC). Non-bovine ruminants such as goats may also be infected and serve as a virus reservoir to be considered in the development of control strategies. To evaluate the susceptibility of caprine airway epithelial cells to infection by viruses of BRDC, we established a culture system for differentiated caprine epithelial cells. For this purpose, we generated precision-cut lung slices (PCLS), in which cells are retained in their original structural configuration and remain viable for more than a week. The three bovine viruses were found to preferentially infect different cell types. Ciliated epithelial cells were the major target cells of BPIV3, whereas BHV-1 preferred basal cells. Cells infected by BRSV were detected in submucosal cell layers. This spectrum of susceptible cells is the same as that reported recently for infected bovine PCLS. While infection of caprine cells by BRSV and BPIV3 was as efficient as that reported for bovine cells, infection of caprine cells by BHV-1 required a tenfold higher dose of infectious virus as compared to infection of bovine airway cells. These results support the notion that non-bovine ruminants may serve as a reservoir for viruses of BRDC and introduce a culture system to analyze virus infection of differentiated airway epithelial cells from the caprine lung.


      PubDate: 2014-03-17T10:06:10Z
       
  • Molecular characterization of a duck hepatitis virus 3-like astrovirus
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Ning Liu , Fumin Wang , Jiajian Shi , Lisha Zheng , Xiaoyan Wang , Dabing Zhang
      Using an ORF1b-based astrovirus-specific reverse transcription (RT)-PCR assay, a duck hepatitis virus type 3 (DHV-3)-like astrovirus was detected from four intestinal samples collected from diseased ducks in China. Complete genome sequencing and comparative sequence analysis showed that the four duck astrovirus (DAstV) isolates were closely related and possessed a typical astrovirus genome organization. Genetic analysis of the complete ORF2 region revealed that mean amino acid genetic distances between the DHV-3-like isolates and previously known avastrovirus species were between 0.579 and 0.721, suggesting that the DHV-3-like isolates could be classified as an additional avastrovirus species. In the ORF1a and ORF1b regions, however, mean amino acid genetic distances between the DHV-3-like viruses and the turkey astrovirus 2 (TAstV-2)-like isolates were substantially less than those between TAstV-2-like isolates and DAstV/C-NGB-like astroviruses belonging to the same species. Pairwise comparisons and phylogenetic analyses demonstrated that the DHV-3-like isolates were most closely related to TAstV-2-like viruses in ORF1a and ORF1b, while showed highest similarity with the chicken astrovirus (CAstV) 612-like viruses in ORF2. These findings provide evidence that recombination events may have occurred during evolution of the avastroviruses and support the view that genomic analysis is required for classification of the avastroviruses.


      PubDate: 2014-03-17T10:06:10Z
       
  • Up-regulation of pro-inflammatory factors by HP-PRRSV infection in
           microglia: Implications for HP-PRRSV neuropathogenesis
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Xin-xin Chen , Rong Quan , Xue-kun Guo , Li Gao , Jishu Shi , Wen-hai Feng
      Atypical porcine reproductive and respiratory syndrome (PRRS) caused by a highly pathogenic PRRS virus (HP-PRRSV) is characterized by high fever, high morbidity, high mortality, and associated with severe neurological symptoms. Microglia are the resident innate immune cells in central nervous system (CNS), and their activation has been implicated as an important contributor to the pathogenesis of CNS diseases. In the present study, we successfully cultured porcine microglia and demonstrated that microglia could support PRRSV infection and replication in vitro. We further showed that HP-PRRSV infection significantly up-regulated the key inflammatory factors including IL-1β, TNF-α, IL-6, IL-12, IL-8, CXCL10, MCP-1, CCL3, CCL4, and CCL5 in cultured microglia as well as in the CNS of HP-PRRSV-infected pigs. The transcription factors NF-κB and AP-1, which are widely reported to regulate cytokine and chemokine productions, were activated by HP-PRRSV infection in microglia. Meanwhile, we found that HP-PRRSV induced cellular ROS formation in microglia and ROS scavenger was proved to significantly abolish the activation of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6, and IL-8), suggesting that ROS are crucial for pro-inflammatory gene production. Importantly, incubation with supernatants from HP-PRRSV-infected microglia cell culture remarkably induced SH-SY5Y neuroblastoma cell death. Collectively, these results showed that PRRSV infection induced cytokine and ROS up-regulation in microglia, which might contribute to neurotoxicity. These data have implications for us to understand the neuropathogenesis of HP-PRRSV in pigs.


      PubDate: 2014-03-17T10:06:10Z
       
  • Innate immune responses of airway epithelial cells to infection with
           Equine herpesvirus-1
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Gisela Soboll Hussey , Laura V. Ashton , Ayshea M. Quintana , David P. Lunn , Lutz S. Goehring , Kristina Annis , Gabriele Landolt
      Equine herpesvirus-1 (EHV-1) is the cause of respiratory disease, abortion and myelitis in horses worldwide. Protection following infection or vaccination is typically incomplete and this lack of protective immunity is thought to be due to the immunomodulatory properties of EHV-1. EHV-1 immune modulation is likely initiated early in the infection cycle at the respiratory epithelium, but to date, immunity to EHV-1 at the epithelial cell barrier remains poorly characterized. Thus, the purpose of this study was to use a recently established primary equine respiratory epithelial cell culture (EREC) system to characterize innate immunity to EHV-1. Differentiated ERECs were inoculated with a neuropathogenic strain of EHV-1 and cytokine responses were determined using quantitative real-time polymerase chain reaction and ELISA. Major histocompatibility complex (MHC)-I and MHC-II as well as toll-like receptor (TLR)3 and TLR9 protein expression were examined using fluorescence activated cell-sorting analysis and chemotaxis of neutrophils and monocytes were evaluated using chemotaxis assays. Infection with EHV-1 resulted in increased expression of TLR3 and 9 as well as inflammatory cytokines (IL-1, TNF-alpha, IFN-alpha, and IL-6) and chemokines (IL-8, MCP-1). In contrast, EHV-1 infection caused marked decreases of MHC-I and MHC-II expression as well as a reduction in IFN-gamma production. In summary, these results provide an initial characterization of the early immune response to EHV-1 at the epithelial cell barrier and show that, while EHV-1 maintains induction of an inflammatory response, it causes an attenuation of IFN-gamma responses and down-modulates expression of MHC-I and MHC-II, which are important molecules for antigen presentation.


      PubDate: 2014-03-17T10:06:10Z
       
  • Chlamydial infections of fish: Diverse pathogens and emerging causes of
           disease in aquaculture species
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): M.C. Stride , A. Polkinghorne , B.F. Nowak
      Chlamydial infections of fish are emerging as an important cause of disease in new and established aquaculture industries. To date, epitheliocystis, a skin and gill disease associated with infection by these obligate intracellular pathogens, has been described in over 90 fish species, including hosts from marine and fresh water environments. Aided by advances in molecular detection and typing, recent years have seen an explosion in the description of these epitheliocystis-related chlamydial pathogens of fish, significantly broadening our knowledge of the genetic diversity of the order Chlamydiales. Remarkably, in most cases, it seems that each new piscine host studied has revealed the presence of a phylogenetically unique and novel chlamydial pathogen, providing researchers with a fascinating opportunity to understand the origin, evolution and adaptation of their traditional terrestrial chlamydial relatives. Despite the advances in this area, much still needs to be learnt about the epidemiology of chlamydial infections in fish if these pathogens are to be controlled in farmed environments. The lack of in vitro methods for culturing of chlamydial pathogens of fish is a major hindrance to this field. This review provides an update on our current knowledge of the taxonomy and diversity of chlamydial pathogens of fish, discusses the impact of these infections on the health, and highlights further areas of research required to understand the biology and epidemiology of this important emerging group of fish pathogens of aquaculture species.


      PubDate: 2014-03-17T10:06:10Z
       
  • Antimicrobial resistance of zoonotic and commensal bacteria in Europe: The
           missing link between consumption and resistance in veterinary medicine
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Lourdes Garcia-Migura , Rene S. Hendriksen , Lorenzo Fraile , Frank M. Aarestrup
      The emergence of resistance in food animals has been associated to the consumption of antimicrobials in veterinary medicine. Consequently, monitoring programs have been designed to monitor the occurrence of antimicrobial resistant bacteria. This study analyses the amount of antimicrobial agents used in nine European countries from 2005 to 2011, and compares by univariate analysis the correlations between consumptions of each of the following antimicrobial classes; tetracycline, penicillins, cephalosporins, quinolones and macrolides. An overview of resistance in zoonotic and commensal bacteria in Europe focusing on Salmonella, Escherichia coli, Campylobacter sp. and Enterococcus sp., during the same period of time based on monitoring programs is also assessed. With the exception of cephalosporins, linear regressions showed strong positive associations between the consumption of the four different antimicrobial classes. Substantial differences between countries were observed in the amount of antimicrobials used to produce 1kg of meat. Moreover, large variations in proportions of resistant bacteria were reported by the different countries, suggesting differences in veterinary practice. Despite the withdrawn of a specific antimicrobial from “on farm” use, persistence over the years of bacteria resistant to this particular antimicrobial agent, was still observed. There were also differences in trends of resistance associated to specific animal species. In order to correlate the use of antimicrobial agents to the presence of resistance, surveillance of antimicrobial consumption by animal species should be established. Subsequently, intervention strategies could be designed to minimize the occurrence of resistance.


      PubDate: 2014-03-17T10:06:10Z
       
  • Extended-spectrum β-lactamase, carbapenemase and AmpC producing
           Enterobacteriaceae in companion animals
    • Abstract: Publication date: 14 May 2014
      Source:Veterinary Microbiology, Volume 170, Issues 1–2
      Author(s): Joseph E. Rubin , Johann D.D. Pitout
      Organisms in the family Enterobactericeae including, Escherichia coli, commonly cause community and hospital-associated infections in both humans and companion animals. The increasing prevalence of infections with organisms producing broad spectrum β-lactamses such as the ESBLs (particularly the CTX-M type), AmpC and carbapenemase enzymes are threatening the future of the β-lactam drugs. While a number of organisms within the Enterobacteriaceae producing these enzymes have been isolated from cats, dogs and horses, E. coli, including isolates indistinguishable from strains found in people, has most frequently been described in the literature. Although little is known about the prevalence of colonization, or incidence of infections with these organisms in companion animals, the growing body of literature suggests that they are increasing. Transmission of these organisms to and from humans into companion animals has not been adequately described, although significant public and animal health concerns exist.


      PubDate: 2014-03-17T10:06:10Z
       
 
 
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